Firing mechanism for a firearm



Jan. 1, 1957 c. A. PERRY ETAL 2,775,837

FIRING MECHANISM FOR A FIREARM Filed Oct. 16, 1952 2 Sheets-Sheet 1 mkm Attorneys Jan. 1, 1957 c. A. PERRY El'AL 2,??533? FIRING MECHANISM FOR A FIREARM Filed Oct. 16, 1 952 2 Sheets-Sheet 2 Uenlors laude fl/fred firry :9 2 a hlaa ran,

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Attorneys.

FIRING NIECHANISM FOR A FIREARM Claude Alfred Perry, Olton, and Roger David Wackrow, Handsworth, England, assignors to The Birmingham Small Arms Company Limited, Birmingham, England, a British company Application October 16, 1952, Serial No. 315,012

Claims priority, application Great Britain August 26, 1952 Claims. (CI. 42-69) This invention relates to firearms (particularly those of the falling-block type) and has for its main-object the provision of a sear mechanism which permits of an extremely short trigger movement, of consistent load, which preferably can be adjusted to the users requirements within predetermined limits.

The invention broadly comprises the operation of the firing pin lever (which allows the release of the firing pin when the weapon is fired) by the interposition between the trigger and the firing pin lever of members which isolate the trigger from the heavy pressure exerted on the firing pin lever by the firing-pin spring.

According to one feature of the invention, the trigger is substantially relieved of the pressure usually exerted through the firing pin lever by the interposition of a spring-loaded sear which, in the cocked position of the weapon, engages the firing pin lever, this sear being adapted, on the firing of the weapon, to be moved out of engagement with the firing pin lever by the operation of a spring-loaded member which, in the cocked position, engages with the trigger sear.

According to a further feature of the invention the spring loaded hammer member is constructed as a hammer lever, so that, on release, it moves under spring pressure into contact with the firing pin lever sear, thereby moving this sear out of engagement with the firing pin lever.

According to a further feature of the invention a common spring provides the necessary spring pressure to the firing pin lever sear and to the spring loaded hammer lever member.

The invention is particularly applicable to firearms having an action of the Martini type, that is to say, an action having a pivoted breech-block, in which the firing-pin is mounted, the breech-block being operated by a cockinglever, and the firing-pin by a firing pin lever (under the control of the trigger on firing and by movement of the cocking-lever on cocking) preferably mounted upon the pivot of the cocking-lever, a combined extractor and ejector of bell-crank formation being provided and operated by engagement with and movement of the breechblock.

The invention will now be particularly described with reference to the accompanying drawings in which:

Fig. l is a sectional elevation of a Martini type action incorporating the invention, the parts of the action being in the cocked position;

Fig. 2 is a similar view to Fig. 1 but shows the position of the parts of the action after the weapon has been fired;

Fig. 3 is a similar view to Figs. 1 and 2 but shows the position of the parts of the action during cocking;

Fig. 4 is a sectional view on the line 4-4 of Fig. 3.

Figs. 5 and 6 are end and side views respectively of the hammer lever member hereinafter referred to;

Figs. 7 and 8 are end and side views respectively of the firing pin lever sear hereinafter referred to;

Figs. 9 and 10 are end and side views respectively of the firing pin lever hereinafter referred to; and

nited States Patent 0 2,775,837 Patented Jan. 1, 1957 Fig. 11 is a view of a spring hereinafter referred to.

In one form, illustrated in the drawings, of carrying the invention into effect in a firearm having a Martini action, the firing pin lever 2 is, in the cocked position, as shown in Fig. 1, engaged by a pivoted sear member 3 which is of bell-crank form. The trigger 5 has an extending arm 6 forming a sear 7 having a knife-edge engagement (for example about 0.008") with an edge of a notch 8 on one arm 9 of a pivotally mounted spring loaded hammer lever member 10, the firing pin lever sear 3a and trigger sear 7 being maintained in engagement with the respective firing pin lever notch 2a and trigger notch 8 through the medium of a light (for example, about 5 lbs.) torsion or mousetrap spring 11 common to the firing pin lever sear 3 and to the hammer lever member 10. This spring is conveniently mounted upon the pivot 12 of the hammer lever member 10 one end 13 of the spring engaging a projection 14 on one arm 22 (i. e. the one which does not carry the sear 3a) of the sear member 3 the other end 15 of the spring engaging the hammer arm 9 of the hammer lever member 10.

A light coil spring 16 (see particularly Fig. 4) is disposed within the trigger guard 17. The inner end of this spring engages the under side of the arm 6 extending from the trigger 5 and assists in maintaining the trigger sear 7 in its cocked engagement with the hammer lever notch 8. The outer end of the spring is engaged by an adjusting screw 19 in the trigger guard. Adjacent to this spring 16 is a screw 21 the inner end 24 of which serves as a stop by engagement with the under side of the arm 6. The two screws 19 and 21 are secured against unwanted rotation by a friction tight locking pin 20 of soft metal or other suitable material.

By an almost imperceptible movement of the trigger 5, the trigger sear 7 releases the hammer lever member 10 which, under the action of the torsion spring 11, swings clockwise and its hammer arm 9 strikes the extending arm 22 of the sear member 3 with sufficient force to cause the sear 3a to release the firing pin lever 2 and the firingpin 23, the latter being under the influence of its spring 24. This movement is particularly illustrated in Fig. 2.

Upon re-cocking of the firearm by the usual cockinglever 23, the lower face 25 of the usual downwardlymoving breech-block 27 strikes an arm 29 (i. e. the arm on the opposite side of the pivot 12 to the hammer arm 9) of the hammer lever member, moving it anti-clockwise against the action of the torsion spring 11 and permitting re-engagement of the trigger sear 7 under the influence of the coil spring 16 beneath it. Simultaneously a cam face 30 on the end of the firing pin lever 2 moves the sear 3 in an anti-clockwise direction, also against the action of the torsion spring 11, and permits re-engagement of the firing pin lever 2 and its sear 2a in the closing movement of the breech block.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

l. Firing mechanism for a firearm comprising a spring loaded firing pin, a firing pin lever releasably holding the firing pin in cocked position, a spring loaded sear member engageable with the firing pin lever when the weapon is cocked and disengageable therefrom to release the firing pin lever to fire the weapon, a trigger, a trigger sear, a hammer lever engageable by the trigger sear when the weapon is cocked and releasable therefrom when the weapon is fired and means for impelling the hammer lever, when released, to strike a blow upon the spring loaded firing pin lever sear member and thereby disengage said sear member from the firing pin lever.

2. Firing mechanism for a firearm comprising a firing pin, a firing pin lever releasably holding the firing pin in cocked position, a spring loaded sear member for the firing pin lever which is engageable with the firing pin lever when the weapon is cocked and disengageable therefrom when the weapon is fired, a trigger, a trigger sear, a pivot, a hammer lever mounted on said pivot, a spring acting to .move said hammer lever around said pivot in a direction to engage said sear member, means for engaging the trigger sear and the hammer lever and for loading said spring when the weapon is cocked, said loaded spring being operative in response to disengagement of the hammer lever from the trigger sear to drive the hammer lever about its pivot to strike the spring loaded sear for the firing pin lever with an impact sufficient to disengage the spring loaded sear member from the firing pin lever and thereby her having a notch therein, a trigger, an arm extending from the trigger, and a sear formed on said arm and releasably engageable with an edge of the notch in the hammer member, said spring which acts on the sear memher also acting on the hammer member to move it in the 4 direction to hold the edge of its notch in engagement with the sear on the arm of the trigger and to drive the hammer member against said sear member with impact sutficient to disengage the sear member from the firing pin lever in response to release of the hammer member by the sear on the arm of the trigger.

4. Firing mechanism for a firearm as defined in claim 3, wherein said pivoted sear member for the firing pin lever is provided with an arm which is in the path of and engageable by said hammer member to disengage the scar on said sear member from said notch of the firing pin lever.

5. Firing mechanism for a firearm as defined in claim 3, wherein said spring, which ,acts to move the scar on said sear member into engagement with the notch in thc firing pin lever is common to said sear member and said hammer member and is held in loaded condition by engagement of the sear on the arm of the trigger with the notch in the hammer member.

References Cited in the file'of this patent UNITED STATES PATENTS 2,249,231 Smith July 15, 1941 2,249,232 Smith July 15, 1941 2,509,540 Sunderland May 30, 1950 2,584,299 Sefried Feb. 5, 1952 

